Type 1 diabetes is a chronic, life-threatening disease that is caused by failure of the pancreas to deliver the hormone insulin, which is otherwise made and secreted by the beta cells of the pancreatic islets of Langerhans. Insulin opens receptors on the cell surfaces, thereby regulating inflow of blood glucose, an essential cell nutrient. With the resulting absence of endogenous insulin, people with type 1 diabetes cannot regulate their blood glucose to euglycemic range without exogenous insulin administration. However, it is critical to provide accurate insulin dosing, so as to minimize and whenever possible eliminate low or high blood glucose levels. Both high glucose levels, known as hyperglycemia, and low glucose levels, known as hypoglycemia, can have debilitating and deleterious consequences. Hypoglycemia may result in a coma and can cause acute complications, including brain damage and paralysis. While severe hyperglycemia can also result in a coma, mild chronic hyperglycemia potentially results in long-term, deleterious, and even life-threatening complications, such as vascular disease, renal complications, vision problems, nerve degeneration, and skin disorders.
In practice, it has been necessary for people with type 1 diabetes to monitor their blood glucose and administer exogenous insulin several times a day in a relentless effort to maintain their blood glucose near euglycemic range. This is a demanding, painstaking regimen. Even those who successfully adhere to the regimen are burdened by it to varying degrees and often still struggle with maintaining good glycemic control. Those who do not follow a regimen are at risk for severe complications.